Nocebo effects occur when an adverse effect on the patient arises from the patient’s own negative expectations. In accordance with informed consent, providers often disclose information that results in unintended adverse outcomes for the patient. While this may adhere to the principle of autonomy, it violates the doctrine of “primum non nocere,” given that side-effect disclosure may cause those side effects. In this article we build off previous work, particularly by Wells and Kaptchuk and by Cohen, to suggest ethical guidelines that permit nondisclosure in the case when a nocebo effect is likely to occur on of the basis of nonmaleficence. We accept that that autonomy vis-à-vis informed consent must be forestalled, but salvage much of its role by elaborating a practical clinical approach to postencounter follow-up. In doing so, we reconcile a clinically practicable process of determining conditions of disclosure with long-standing ethical commitments to patients.